Voyager 1 data challenges long-held theories about our solar system

June 29, 2013 by  
Filed under Wind Energy Tips

Now that NASA’s Voyager 1 space probe, launched back in 1977, has arrived at the edge of the solar system on the very cusp of interstellar space, it is transmitting data that has scientists scratching their heads. In three studies published Thursday (June 27) in the journal Science, researchers describe the strange area across which Voyager 1 has been travelling at a speed of about one million miles per day.

The newly discovered region, which NASA has named the ‘magnetic highway,’ is located in the heliosphere, the bubble of charged particles surrounding the solar system that is created by powerful solar winds. These winds emanate out from the sun at a tremendous speed until they reach interstellar space, also known as the local interstellar medium. When the winds reach the local interstellar medium, the heliosphere forms and acts as a kind of shield that protects our solar system from cosmic rays.

The boundary between the heliosphere and the local interstellar medium is called the heliopause. When solar winds hit this region, they slow down dramatically, causing a shock wave called the solar wind termination shock. As a result of this shock wave, charged particles accelerate and help the formation of the heliosphere. The region of space beyond the termination shock is known as the heliosheath, where the solar wind, now slowed and compressed, churns violently by its interaction with the interstellar medium.

What has scientists puzzled is that Voyager 1’s data from the edge of the solar system has turned their predictions about the heliosphere upside down. Specifically, there are three anomalies that have them stumped. For one thing, back in July of 2012, the data showed that while solar winds had dropped by half, the strength of the magnetic field almost doubled. These readings reversed themselves several times before stabilizing on August 25. Since that time, there has been a dramatic reduction in solar particles along with a simultaneous increase in high-energy cosmic rays emanating from deep space. Because of the marked variations in readings, scientists believe they have encountered a boundary unlike anything observed previously. They call this boundary the ‘heliosheath depletion region.’

The second thing baffling researchers is that despite evidence that Voyager is at the farthest edge of the solar system, the direction of the magnetic field remains mostly unchanged. Some theorize that that the continuing strength of the magnetic field is caused by spiraling magnetic fields as they are pushed against the interstellar medium. Others contend this is impossible due to the apparent absence of solar winds. Another possibility is that a process called ‘magnetic reconnection’ is occurring, where the sun’s magnetic fields have joined in places with the interstellar magnetic field. The bottom line is that scientists just don’t know.

The third conundrum involves the cosmic rays encountered by the spacecraft–they are not uniformly distributed, but moving in a parallel direction.

“This was conceptually unthinkable,” said Stamatios Krimigis, a solar physicist at Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, in an interview with the Los Angeles Times. “There is no cosmic ray physicist I know who ever expected that they would not all be coming equally from all directions.”

One thing is clear: the scientific community will be keeping a close eye on Voyager 1 as it continues its journey into the celestial unknown.

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